1. Field of the Invention
This invention relates to a box for the installation of electrical apparatus in a raceway for electrical cables, which box is organized in such a way that, once it has been fitted in the raceway, the electrical apparatus has been mounted therein and has been electrically connected, it is provided with means allowing it to be locked in place in the raceway, making sliding thereof longitudinally along the raceway impossible.
In particular, this box includes means for fixation thereof in a raceway for electrical cables, especially a raceway of the type formed by the association of a base section and a cover section, formed by extrusion of a thermoplastic insulating material, in which the base section is provided longitudinally on the inside of the edges of the walls thereof with overhanging shaped tubular beads, each of which is formed with an upper longitudinal groove for engagement with ribs provided on the cover section, and a lower inverted spine opposite said groove.
2. Prior Art
With the purpose of holding the electrical apparatus assembly box immobile in the raceway and, particularly, in the longitudinal direction of the latter, solutions have been adopted based on screwing the box to the raceway, which required drilling operations on the raceway, in the arrangement of auxiliary abutment members, which makes the product and the assembly operation more expensive, and other fixing arrangements, none of which has been effective.
Under these circumstances, it would be desirable to have an electrical apparatus assembly box which, by way of a peculiar organization of the normal elements thereof, allowed it to be held immobile in the raceway in a simple, direct way.
In accordance with the foregoing ideas, the solution of providing the assembly box with means for fixation to the raceway, based on systems of pressing the box against the raceway, has been adopted.
According to the foregoing solution, the box for the installation of electrical apparatus in a raceway for electrical cables of the invention has been developed. The box is formed by an upper portion, which may be engaged in the grooves of the shaped tubular beads of the base section of the raceway and is provided with means for fixation of the electrical apparatus and of association with a lower portion which, located with a slight clearance below the said upper portion, is provided with means for seating on the inverted spines of the said shaped beads and with mating means of association with the upper portion which determine the moving together of both portions and the clamping of said shaped beads therebetween.
One preferred embodiment is constituted by a box which is formed by an upper portion which, in framelike fashion, comprises means for the seating and fixation of the apparatus and for the engagement of said portion in the grooves of the shaped beads of the base section of the raceway, in the same way as the cover section engages therein, and a lower portion which, suspended under said upper portion, forms the box proper for protecting the apparatus and is provided with means for engagement in said grooves, and of means for seating on the lower inverted spine of said overhanging shaped beads of the base section, both the upper and the lower portions having mating means for the firm mutual association thereof, determining the clamping of said shaped beads of the raceway therebetween.
One feature of the invention consists of the upper portion having the corners thereof cutaway for the passage of the engagement means provided on the lower portion for engagement thereof in the grooves of the shaped beads of the base section of the raceway.
A further feature of the invention resides in the fact that the means provided in the lower portion for the seating thereof on the inverted spines of the shaped beads of the base section of the raceway are formed by respective barb-like projections which are disposed on opposite surfaces of the lower portion which are parallel to the walls of said base section and have a surface parallel to the surface of the upper portion.
Yet a further feature of the invention resides in the fact that the means for the mutual association of the upper and lower portions which determine their mutual moving together and the clamping of the shaped beads therebetween are formed by self-tapping screws which pass through respective holes in the upper portion and penetrate firmly in blind holes provided in the walls of the lower portion, both in those which contain the barb-like projections and in the remaining ones disposed crosswise relative to the raceway.
The invention envisages that the upper portion has respective closure skirts on two opposite sides which overlap the outer surfaces of the walls of the box which are crosswise relative to the raceway.